Create a Serverless Calculator API

### Description
The goal is to create a Rest API calculator which is backed by the Serverless framework.
The calculator API should have 4 endpoints, all of them should be a GET endpoint that accepts two variables as query parameters

- /add
- /subtract
- /divide
- /multiply

### Details
- Technical Specifications:
- Use `python` as the language for the handlers
- assume the cloud provider as `aws`
- 4 handler files, name them as `endpoint_handler.py`
- Create an offline dev server using `serverless-offline`
- Type of issue: Single
- Time Limit: 2 days

### Issue requirements / progress
- [ ] Create the handlers.
- [ ] Create `serverless.yml`.
- [ ] Local testing
- [ ] (optional) create a free AWS account and create a live deployment using `serverless deploy`

### Resources
- https://www.serverless.com/examples/aws-python-rest-api
- https://github.com/serverless/examples/tree/master/aws-python-rest-api
- https://github.com/dherault/serverless-offline

### Directory Structure
Create a folder named `serverless-calculator` in the `Development` folder and place the appropriately named files inside this folder.

#### Note
1. Please claim the issue first by commenting here before starting to work on it.
2. Once you are done with the task and have created a Pull Request, please tag @ to request a review.